Interpretive Summary: Infections by the single-celled parasite Toxoplasma gondii are widely prevalent in animals and humans. If causes mental retardation and loss of vision in congenitally-infected children. It is also a significant cause of mortality in zoo animals. Scientists at the Beltsville Agricultural Research Center and the Houston Zoo report, for the first time, fatal toxoplasmosis in dik-dik. These results will be of interest to wildlife biologists, parasitologists and pathologists.

Technical Abstract:
Acute toxoplasmosis was diagnosed in 2 captive dik-dik (Madoqua guentheri smithi) in the Houston Zoo. Both animals became ill suddenly and died in spite of supportive therapy. Toxoplasma gondii was identified in tissues of both animals immunohistochemically, and antibodies to T. gondii were found in titers of 1:800 or more in both animals examined by the modified agglutination test. The cause of death was considered to be toxoplasmic pneumonia. This is the first report of toxoplasmosis in Madoqua guentheri smithi.